Barack Obama's performance in the first 100 days of his presidency draws strong public approval in a new Washington Post-ABC News poll, but there is decidedly less support for his recent decision to release previously secret government memos on the interrogation of terrorism suspects, an initiative that reveals deep partisan fissures.

Overall, the public is about evenly divided on the questions of whether torture is justifiable in terrorism cases and whether there should be official inquiries into any past illegality involving the treatment of terrorism suspects. About half of all Americans, and 52 percent of independents, said there are circumstances in which the United States should consider employing torture against such suspects.

Barely more than half of all poll respondents back Obama's April 16 decision to release the memos specifying how and when to employ specific interrogation techniques. A third "strongly oppose" that decision, about as many as are solidly behind it. Three-quarters of Democrats said they approve of the action, while 74 percent of Republicans are opposed; independents split 50 to 46 percent in favor of the decision.

The release of the documents, which was fiercely debated at high levels within the government, met with quick fire from former vice president Richard B. Cheney, who said last week that companion memos showing the "success of the effort" should be declassified as well, arguing that the methods had "been enormously valuable in terms of saving lives, preventing another mass casualty attack against the United States."

Defense Secretary Robert M. Gates, who served in the same position in George W. Bush's administration, supported the release of the documents but said it made him "quite concerned with the potential backlash in the Middle East and in the theaters where we are involved in conflict -- that it might have a negative impact on our troops."

Americans also split about evenly on whether the new administration should investigate whether the kind of treatment meted out to terrorism suspects under the Bush administration broke laws, with 51 percent in favor of such inquiries and 47 percent in opposition. About seven in 10 Democrats support such action; a similar proportion of Republicans opposes it. As a candidate, Obama said: "I would not want my first term consumed by what was perceived on the part of the Republicans as a partisan witch hunt, because I think we've got too many problems to solve."

The lukewarm response to Obama's actions on this front stand in stark contrast to his high ratings on handling terrorism and the wars in Iraq and Afghanistan. Most of those polled said that, in general, his policies had either made the country safer from terrorism (32 percent) or not made much of a difference either way (43 percent).

Obama's overall rating remains high, with 69 percent of Americans approving of his job performance. He gets solid marks for his handling of the economy, maintaining a better-than-2-to-1 advantage over congressional Republicans on the issue. Majorities said that Obama has exceeded their expectations in his first three months in office, has accomplished big things and has kept his main campaign promises. Further, public optimism about the economy and the country's direction also remain on the rise since his election, even as few think his major economic initiatives have moved the needle on the nation's flagging economy, their communities or their finances.

Two-thirds of those polled approve of how Obama is handling international affairs in general, up slightly from last month, just before he embarked on his first European trip. Majorities of Americans also approve of how he is handling health care, global warming, taxes and Cuba, four areas in which the administration has tried to stake new ground in its first few months.

But Obama receives less glowing reviews on his handling of the burgeoning federal budget deficit and on immigration issues, where he is at the 50 percent mark, and he gets a negative rating on how he has dealt with the big U.S. automakers.

Beyond specific policy areas, Obama continues to get high personal favorability ratings across a range of attributes. Overall, 72 percent of Americans have a favorable impression of the new president, down slightly from the eve of his inaugural but far higher than it was during the 2008 campaign. It is also about double Bush's favorability rating when he left office in January (37 percent) and above where Bill Clinton's was at this stage in 1993 (59 percent).

Nearly two-thirds said Obama has accomplished "a great deal" or "a good amount" in his first three months in office. In a Post-ABC poll at the 100-day mark in Clinton's first term, 37 percent said he had done that much. A majority, 54 percent, also said Obama had exceeded their expectations, significantly more than had said so of Clinton or Bush at the outset of their first terms.